Compounded hydrocarbon oils and addition agents therefor



Patented Oct. 6, 1953 test AVAiLABLEfiGPY OOMPOUNDED HYDBOCARBON OILS AND ADDITION AGENTS THEREFOR Edward Mitchell, Pittsburgh, and Willard B- Morse, New Remington,

Pa, assignors to Gulf Research 8; Development Company, Pittsburgh, Pa a corporation Delaware No 1mm. Application Julie 7, 1951, Serial No. 230,422

20 Claims. (01- 252-333) This invention relates to addition agents for hydrocarbon lubricating oils in the nature of detergents and rust preventives. In particular the invention relates to new salt compositions. More particularly the invention is concerned with compounded hydrocarbon lubricating oils.

In the lubrication of internal combustion engines of all types, particularly when severe operating conditions are encountered, plain hydrocarbon lubricating oils frequently prove unsatisfactory in service. Furthermore, many lubricating oils which may be highly satisfactory for the lubrication of other mechanisms have been found wholly unsuitable for use as turbine oils.

Hydrocarbon lubricating oils are often objectionable because of deposition of sludge, carbonaceous materials, or varnish and because they fail to prevent the formation of rust. Consequently one or more addition agents are usually employed. For example. in order to counteract the tendency of lubricating oils to form deposits of gum and sludge, additives of a detergent nature are usually incorporated into such oils. To combat the formation of rust, rust-inhibiting agents are generally employed.

It is an object of this invention to provide an a.

addition agent for hydrocarbon oils which functions both as a detergent and as a rust-preventive compound.

The lubricating compositions of the present invention comprise a hydrocarbon lubricating oil and a small amount of a polyvalent metal salt of the condensation product of an alkanethiol containing one to 17 carbon atoms with a monoamide of an unsubstituted or alkvl-substituted dicarboxylic acid as defined below. These metal salts are derivatives of 2,5-endoethylene-A== cyclohexene-l,6-dicarboxylic acid and the corresponding alkyl-substituted acids having not more than four alkyl groups each of not more than six carbon atoms. The N- substituents of the compounds are selected from hydrogen, alkyl and alkenyl radicals, and the total number of carbon atoms in the N- substituents is 8 to 22. At least one N- substituent must bean alkyl or alkenyl radical as defined. l

The metal salts incorporated in hydrocarbon l bricating oils in accordance with the invention 0 n be prepared in any suitable manner. We prefer, however, to prepare the alkanethiol-dicarboxylic acid monoamide condensation product and thereafter prepare the metal salt of this product. The reaction between the alkanethiol and the dicarboxylic acid monoamide is a con. ventional condensation reaction which results in the addition of an alkyl thio radical to one carbon atom of an unsaturated linkage and hydrogen to the other carbon atom of this linkage. Thus, in cases where the N- substituents of the monoamide employed are either hydrogen and an alkyl radi- 08.1 or two alkyl radicals, the condensation product is a 2,5-endoethylene-aikyl thio-cyclohexane- 1,6-dicarboxylic acid monoamide or the corresponding aikyl-substituted compound. The aikyl thio radical will be attached to the carbon atom in either the 3 or the 4 position of the cyclohexane ring.

In cases where the alkanethiol is condensed with a dicarboxylic acid monoamide having an aikenyl radical as an N- substituent, the condensation may take place either on the unsaturated linkage of the cyclohexene ring or on the unsaturated linkage of the alkenyl radical, and it is probable that condensation will take place on both unsaturated linkages.

It will be understood that the particular method of preparing the monoamide of the dlcarboxylic acid employed for reaction with the alkenthiol forms no part of the present invention and that this compound can be prepared in any suitable manner. However, a preferred method of preparing the monoamlde is disclosed in the copending application of Edward Mitchell, Serial No. 230,421, filed of even date herewith. The process as disclosed in the application comprises reacting a cyclohexadiene-L3 compound with an alpha-beta ethylenic dicarboxylic acid containing not more than eight carbon atoms, such as maleic, citraconic, fumaric, glutaconic acids and their geometric isomers such as mesaconic acid and the like. Since the acids and the anhydrides are equivalents, the acids and the anhydrides are included when reference is made either to the acid or the anhydride unless otherwise indicated. The reaction between the cyclohexadiene-1,3 compound and the ethylenic dicarboxylic acid is essentially a Dials-Alder reaction. The resulting reaction product is then reacted with an amine under conventional amidating conditions to form the monoamide.

The diene compounds disclosed are cyclohexadieneqlxb-methyi cyclohexadiene-1.3, the dimetinvl cyclohexadienes such as 4,6-dimethyl cyclohexadiene-l,8, and 2,4-dimethyi cyclohexadiene-1,8, the trimethyl cyclohexadienes such as 4,5,5-trimethyl cyclohexadiene-l,3 the methyl isopropvl cyclohexadienes such as alpha-terrainone, also Lil-dimethyl-3-ethyl-oyclohexadiene- 1.8, l-methyl-S-ethyl-i-isopropyl cvclohexadiens-1,3, l-methyl-B-isobutyl. cyclohcxadiene-l,3, and l-methyl-B-n-hexyl cyolohexadiene-1.3.

An alkyi-substituted 2,5-endoethy1ene-A== BEST AVAiLABLE CQPY .aeeeyoe N-substituents are either hydrogen and an alkyl radical or two alkyl radicals there is no advantage in using more than one moi of the alkanethiol, However, when an alkenyl radical is an N-substituent, a larger amount of the alkanethioi can advantageously be used since, as pointed out previously, condensation may take place in the alkylene radical as well as in the cyclohexene ring. In condensing the alkanethiol with the monoamide so formed, it is generally desirable to employ a temperature of from about 100 I". tothe'boiling point of the particular alkanesuch a carbon atom may contain-an aliryl sub-- 1 stituent in any case. For example, when cycloheXadiene-LS is condensed with citraconic acid,

the resulting cyclohexene-Lc-dicarboxylicacid will contain one alkyl substituent and this a methyl group attached to a carbon atom towhieh a carboiwl group is also attached. Also, it will be noted that when an acid, such as glutaeonic acid, in which the two carboxyl groups are not both attached to the carbon atoms forming the ethylenic double bond, is employed, the iinal cyclohexene dlcarboxylic acid will be one in which a carbonyl group is linked to the cyclohexene ring through an alkylene radical. Such compounds are equivalent to those in which both carboxyl groups are attached directly to carbon atoms of the cyclohexene ring and are included when the 2,5-endoethylene-A'"-cyclohexene-l.8- dicarboxylic acids are referred to, unless otherwise indicated,

The amines which are employed in the formation of monoamides as disclosed in said copending application are primary allwl or alkenyl amines having from 8 to 22 carbon atoms, and secondary alkyl and alkenyl amines having a total of from 8 to 22 carbon atoms. Examples of suitable amines are octyl amine, decyl amine. undecyi amine, dodecyl (lauryl) amine, tetradecyl amine, octodecyl amine, diamyl amine, dibutyl amine, N-butyl-decenyi amine, octenyl amine, decenyi amine, undecenyl amine, dodecenyl amine, tetradecenyl amine, hexadecenyl amine, and 'octadecenyl amine. Mixtures of amines such as are commercially available are desirable, for example mixtures of primary alkyl amines derived from fatty acids. These will be agoiines having approximately 8 to 22 carbon a ms.

In the preparation of the novel compounds in accordance with the present invention, the metal salt described in application U. 8. Serial No. 230,421, can be condensed with an alkanethiol having 1 to 17 carbon atoms in the alkyl group. However, as stated above. it is preferred to start with the monoamide of the dicarboxylic acid mentioned supra. Without limiting ourselves to any theory we believe that since the alkanethiols, are acidic in character the metal may be displaced in part if the metal salt is employed instead of the monoamide.

In preparing the metal salts of the instant invention by the methods mentioned above, equivalent amounts of the Various reactants are preferably used. Thus about one moi of the dime, such as alphs-terpinene, can be reacted with about one moi or the acid, for example, maleic anhydride. at a temperature of from about soo F. to about 840' I". The monoamide can then beprepared by adclns about one moi oi the amine at a temperature from about no I. to. about 200' l". The alkanethiol derivative is preferably prepared by condensing said monoamide with about one moi of the alkanethiol. Where the thiol employed. As an example, when 2-methylpropanethlol-l is .used, we prefer a temperature from about F. to about 190 F., which is the boiling pointof the z-methyl-propanethiol-l. If

the alkanethiol has a boiling point below about 100511. asdoes methanethiol, it is necessary to carry out the reaction under pressure, for example. in an autoclave. In addition, it is obvious that if the boiling point of the alkanethiol is above the decomposition temperature of the monoamide, a temperature below said boiling Point must be used. In this case, it is desirable to heat the reaction mixture at a temperature of from about F. to about F., usually for about one hour. The monoamide-alkanethiol condensation product so formed can then subsequently be neutralized with about one equivalent weight of a base such as barium hydroxide to form the metal salt.

The polyvalent metal salts can be prepared directly, that is, by neutralization or treatment with the metal oxide; or they can be prepared indirectly by double decomposition or metathesis. Desirable metals employed in the Salt-forming reaction are barium, magnesium, calcium, nickel, zinc, lead, copper, strontium, aluminum, bismuth, iron, chromium and the like.

In some cases, selection of the particular alkanethiol may depend somewhat on steric hindrance. Thus, if a long chain amine was used it may be desirable to employ a short chain aikanethiol. While suitable alkanethiols will readily be known to those skilled in the art, the following are mentioned by way of example: methanethiol, ethanethiol, l-propanethiol, 2- propanethiol, i-butanethiol, z-methyl-propanethiol-i, i-pentanethiol, s-pentanethiol, decanethiol, dodecanethiol, octanethlol and cetanethiol.

when the unsaturated acid is contacted with the cyclohexadiene-1,8, some undesired polymer is normally formed. It is desirable to remove this polymer, which is conveniently accomplished by treatment of the final salts. The treatment preferably involves extraction with a solvent. The salts can be readily dissolved in common solvents such as benzene, Stoddard solvent, chloroform and light hydrocarbon oils. The solution is then filtered and, in the case of a volatile solvent, heated to evaporate said solvent. Inasmuch as oil concentrates of the salts of the present. invention are desirable for use, it is preferred to extract the salt using a light hydrocarbon lubricating oil. a

The following examples illustrate the various methods of preparing our improvement agents and improved compositions containing the same.

trample I In this example 28.8 parts by weight of dipentene were heated to a temperature of from 300' I". to 840' 1". for about 30 minutes to rearrange the double bonds in the dipentene molecule to form a conjugated system, the product BEST AVAILABLE COPY 5. being alpha-terpinene, l-methyl-4-isopropyl-cyclohexadiene-1,3. .To this product 16.3 partsby weight oi maleic anhydride were added. The reaction :temperature was maintained at 300 F. to 320 F.'ior one hour. The temperature oi the reaction mixture "was then lowered to about 200 F.-and-41.3parts by weight oi hexadecyl amine wereadded portion-wise. Aiter completing the addition oi the hexadecyl amine-the reactants were maintained 'at a temperature oi 180 F. to 220' F. ior 30 minutes. The reactants were cooled to a temperature oi irom 150 F. to 160' F. and 15.4 parts by weight oi tertiary butyl mercaptan were added, and the reaction temperature was maintained at 150' I'. to 160' F. ior one hour. At the end oi the hour 8.5 parts by weight oi magnesium oxide were added and the reactants were heated at about 180 1''. for about one hour. The product was then extracted with a volatile solvent, iiltercd, and the solvent removed by distillation. The magnesium salt thus prepared had the iollcwing properties:

Appearance Amber solid Neutralization No. 0.86

Percent ash as MgO 4.05

Percent suliur 1.70

Example It In this example 22.8 parts by weight oi alphaterpinene were heated to a temperature irom 300 F. to 320' F. Then 16.7 parts by weight oi maleic anhydride were slowly added and the heating continued at a temperature oi 300 F. to 320 F. ior one hour. The reactants were cooled to a temperature oi irom 200' F. to 210' F. and 41 parts by weight oi a mixture oi amines were added, the temperature being maintained at 200 F. to 210' F. ior 30 minutes. The composition oi the mixture oi amines was 90% hexadecyl amine, 6% octadecyl amine, and 4% octadecenyl amine, To the monoamide so iormed 15.3 parts by weight oi n-butyl mercaptan were added and the mixture was heated to a temperature oiirom 150' F. to 160' F. ior 60 minutes. Then, 4.2 parts by weight oi magnesium oxide were added and the reaction mixture was agitated at a temperature oi irom 200' F. to 212' I". ior at least 60 minutes. The magnesium salt so iormed was extracted with a volatile solvent, filtered and the solvent removed by distillation.

trample III a In this example 23.6 parts by weight oi alphaterpinene were heated to a temperature oi 300 1". Then, 17.0 parts by weight oi maleic anhydride were slowly added and the heating continued at a temperature oi 300' F. to 320 F. ior one hour. The'reactants were cooled to a temperature oi irom 200' F. to 260' I". and 43.3 parts by weight of a mixture oi amines were added, the temperature being maintained at 200 1''. to 250 F. ior 16 minutes. The composition oi the mixture oi amines was 90 per cent hexadecyl amine, 6 per cent octadecyl amine and 4 per cent octadecenyl amine. To the monoamide so iormed 12.? parts by weight oi n-propanethiol were added and the mixture was heated to a temperature oi irom 160' 1". to 160 I". ior minutes. Then, 3.6 parts by weishtoi magnesium oxide were added and the reaction mixture was agitated at a temperature oi irom 1801*. to 190' 1". ior at least 60 minutes. The magnesium salt so iormed was ex- Example IV In this example, 20.! parts by weight oi alphaterpinene were heated to a temperature from 300 F. to 320 F. Then 14.9 parts by weight of maleic anhydride were slowly added and the heating continued at a temperature oi 300 F. to 820 1''. ior one hour. The reactants were cooled to a temperature oi irom 190 F. to 200 F. and 36.0 parts by weight ci a mixture oi amines were added, the temperature being maintained at 190' F. to 200 F. ior 30 minutes. The composition 0! the mixture of amines was 25 per cent hexadecyl amine, per cent octadecyl amine and 5 per cent octadecenyl amine. To the monoamide so iormed, 13.9 parts by weight oi tertiary butyl mercaptan were added and the mixture'wa's heated to a temperature oi irom 1". to F. ior 60 minutes. Then, 4.3 parts by weight oi barium oxide were added and the reaction mixture was agitated at a temperature oi irom 180' F. to 200 F ior at least 60 minutes. The barium salt so iormed was extracted with a volatile solvent, filtered and the solvent removed by distillation.

Example V In this example, 22.! parts'by weight oi alphaterpinene were heated to a temperature from 310' F. to 320 F. Then, 16.6 parts by weight oi maleic anhydride were solwly added and the heating continued at a temperature oi 310 F. to 320 F. ior one hour. The reactances were cooled-to 200 F. and 41.4 parts by weight of a mixture oi amines were added, the temperature being maintained at 200 F. ior 30 minutes. The mixture oi amines was composed oi 90 per cent hexadecyl amine, 6 per cent octadeoyl amine and 4 per cent octadecenyl amine. To the monoamide s0 iormed, 15.2 parts by weight oi tertiary butyl mercaptan were added and the mixture was heated to a temperature oi 150 F. ior 60 minutes. Then, 4.1 parts by weight oi magnesium oxide were added and the reaction mixture was agitated at a temperature oi irom 210 I". to 215' F. ior at least 60 minutes. The magnesium salt so iormed was extracted with a volatile solvent. filtered and the solvent removed by distillation.

Example W In this example, 47 parts by weight oi alphaterpinene were heated to a temperature from 300 I". to 820' I". Then, 34 parts by weight oi maleic anhydride were slowly added and the heating continued at a temperature oi 300 F. to 320' 1". ior one hour. The reactants were cooled to a temperature oi irom 200 F. to 210 F. and 100 parts by weight oi a mixture oi amines were added, the temperature being maintained at 200' F. to 210' F. ior 80 minutes. The composition oi the mixture oi amines was 90 per cent hexadecyl amino, 6 per cent octadecyl amine and 4 per cent octadecenyl amine. To the mono amide so iormed, 84 parts by weight oi cetyl mercaptan were added and the mixture was heated to a temperature oi irom F. to 160 F. ior 60 minutes. Then, '1 parts by weight oi magnesium oxide were added and the reaction mixture was agitated at a temperature oi irom 200 F. to 212' I". ior at least 60 minutes. The magnesium'salt so iormed was extracted with a volatile solvent, filtered and the solvent removed by distillation.

The salts prepared in accordance with this tracted with a light hydrocarbon lubricating oil. 76 invention are excellent addition agents ior hy- BEST AVAiLABLE COPY aeeavoc drocarbon lubricating oils. Concentrates can be readily prepared as described above and the salts can be added to lubricating oils in the form of such concentrates. Also, the salts can be added directly to the lubricating oil in the desired proportions. All types of hydrocarbon oils, including mineral oils, such as parainnic, naphthenic, and mixed-base mineral oils. can be employed.

As stated. our new addition agents are remark-. ably effective in inhibiting rust and in improving detergent properties of hydrocarbon lubricat- 5 on this arbitrary scale which ranges from 10 (no varnish formed) to (very heavy varnish formation) representing increasing discoloration of the piston skirt. The data obtained in these tests on the following compositions is summar- 0 ised below. The percentages are by weight of the compositions.

in; oil compositions. For this purpose small amounts of the addition agents are generally suf- 831 if 1 3%??? iicient. For example, the addition agents of the instant invention may be added to hydrocarbon 10 pm Lubricating oil. lubricating oils in minor amounts, say from 0.1 to mo M 86 0.1 per cent by weight of;the hydrocarbon oil. Magnesium Baltprepared sufficient to inhibit rust formation. Llller g m g ggfi M m m m amounts of our addition agent, from 0.1 to about manna I Composition Length r n in W of Test,

Hm N of No of No of No i Piste P1 to Piste Pi t 00101 0310? com; 133;; e313? gggg 24.. 2+ 0 10 o 10 0 1o 0 4a.. 0 1 9+ 0 10 o 72.. e o s 0 0+ 0 0a.. is 0 0+ 0 no 4+ [freed s 0 9+ 0 144.. 5 o a o is i 1 0 3i 2 21eII.....-.. 4+ 0 8 8 s+ o 1 Mechanical Niura.

per cent by weight or the hydrocarbon oil, confer excellent detergent properties on the oil solution. Table I following illustrates the remarkable detergent eflects of the new addition agents. The oil employed as the base oil in these compositions was a solvent-refined Mid- Continent oil of lubricating grade having the following characteristics:

this invention, eilects a fourfold increase in the t: time required for ring-sticking to occur in a diesel engine. The tests show marked improve- Gmvuy' a AP! 284 ment in a ring-sticking and in piston color over Viscosity, nos 0 100- r 484 hm Viscosity, sue a 210- r 01.7 In Order to demonstrate the anti-rust proper- Viscosity Index 98 ties of the compositions prepared in accordance Flash point, r 480 with this invention. an oil containing a small Pour point, 1" -5 mount 1 he magnesium salt was subjected to sulfur t 0J7 the test specified in the "ASTM Standards on Pe- Carbon'residue. per cent 0.06 5 "01911111 r and Lubricants," September Neutralization No 0.0a 1945. nd desisnated as ABTM D-665-44T. In

These compositions were tested in a standard Lauson engine for their ability to prevent ringsticking. This test consists in placing 2.1 pounds of the composition in the crankcase of the Lauson engine so modified and so operated as to make the conditions comparable to those prevailing in high-speed automotive-type'diesel engines. The engine is operated under a s H. P. load at 1850 R. P. M. maintaining a cooling Jacket temperature of 300' It. an oil temperature of 225' F. and an air-to-fuel ratio of 18:1; At the end of 24 hours operation under these conditions the engine is stopped. disasembled, and the pistonisexaminedastostuckrinssanddis coloration. If there are no stuck rings, the engine'is reassembled, the oil charge is brought up to 2.1 pounds, and operation is oonltinueg for another 24-hour This proce ure repeated until one m rings sticks or until a brief, the test consists in placing a 300 ml. sample of the oil or oil composition to be tested in a 400 ml. beaker which is immersed in a constant temperature bath maintained at 140 F. The beaker is iltted with a cover provided with openings for a stainless steel motor-driven stirrer and for insertion of a standard steel test bar, y; inch in diameter and 5% inches long, which has 5 been very carefully cleaned and polished Just prior to the test. The stirrer is started. and when the oil sample in the beaker reaches a steady temperature of 140' F. the test bar is inserted in the proper opening and hangs suspended from the beaker cover. After 30 minutes,

30 ml. of distilled water are added to the beaker, and .ltirring is continued for 48 hours, after which time the test bar is removed and examined for rust spots. In carrying out this test 0.05 per cent by weight on the oil of the magnesium salt An oil containing a small amount oi the addition BEST AVAiLABLE COPY 9 prepared in accordance with Example I was used. The oil employed in the test was an aluminum chloride-treated parailinio oil having a viscosity oi 150 S. U. B; at 100' l". A test was carried showed signs'oi rust wtihin three-hours.

The above tests show the remarkable rust-inm hibiting and detergent-conferring properties oi the additives prepared in accordance with the instant invention. Hydrocarbon oil lubricant compositions containing our new addition agents are thereiore suited for use where operating conditions are extremely severe, as in diesel, tank and truck engines, and in"the lubrication oi steam turbines-i; Moreover, the addition agents oi the present. invention cooperate eiiectively. with otheradditives. Other known addition agents which may be incorporated into lubricating compositions prepared in accordance with our invention are,\ior example, pour point dopressants, extreme premure agents, and the like.

as agent oi this invention in combination with a commercial oxidation corrosion inhibitor was tested in a Chevrolet engine. Both the piston varnish rating and the combined engine varnish and sludge rating were periect, indicating that the detergent oi the present invention does not appreciably anect the bearing corrosion value, but cooperates with the commercial corrosion inhibitor.

While we have shown in the examples the preparation oi compounded lubricating oils, our invention is notlimited thereto but comprises other hydrocarbon oil lubricant compositions containing our new addition agents such as greases and the like. Obviously many modifications or variations of the invention as hereinbeiore set iorth may be made without departing from the spirit and scope thereoi and. therefore, only such limitations should be imposed as are indicated in the appended claims.

We claim: 1. A lubricant composition comprising a major amount of a hydrocarbon lubricating oil, and ;a minor amount, suihcient to impart rust-inhibiting properties to the composition, oi a polyvalent metal salt oi the condensation product oi (1) an alkanethiol having 1 to 1'! carbon atoms in the alkyl group and (2) a monoamide oi a dicarboxylic acid wherein the two N- substituents are selected from the group consisting oi hydrogen. alkyl and alkenyl radicals, at least one substituent being an organic radical oi saidgroup, and wherein the total number'oi carbon atoms in the N- substituents is 0 to 22,. and wherein said dicarboxylic acidds selected from the group 'con-' sisting-01 unsubstitutedandjalhl-substituted 9 2,5-endoethylen'e- A==!-cyclohexene-1,6-dicarboxylic acids, sald alkyl-substltuted dlcarboxyllo acid having not more than iour alkyl groups each having not .more-thsno carbon atoms.

2. A lubricant composition comprising a major amount oi ai hydrocarbon lubricating oil and a minor amount, siu'iicient to conier detergent ro erties on thecomposition. oi a polyvalent metal salt oi the'eondens ationproduct oi'.(1) an aikanethiol havingi1' to 17 carbon atoms in the. alkyigroup and (2) a monoamideoiadicarboxylic acid wherein the two N- substituents are selected irom thegroup consisting oi hydrogenpalkyl and radicals. at least one sub- 7s stituent being an organic radical of said group, and wherein the total number oi carbon atoms in the N- substituents is 8 to 22, and wherein said dicarboxylic acid is selected from the group consisting oi unsubstituted and alkyl-substituted 2, 6-endoethylene-A== -cyclohexene-1,6-dicarboxylio acids, said alkyl-substltuted dicarboxylic acid having not more than four alkyl groups each having not more than 6 carbon atoms.

8. Alubricant composition comprising a major amount of a hydrocarbon lubricating oil and 'about 0.01 to 20 per cent by weight oi said oil of a polyvalent metal salt oi a monoamide oi a dicarboxylic acid selected irom the group consisting oi 2.5-endoethylenealkyl thio-cyclohexane-1,8-dicarboxylio acid and alkyl-substituted 2,5-cndoethylene-aliryl thio-cyclohexane- -1,6-dicarboxylic acids which contain not more than iour alkyl groups each having not more than 6 carbon atoms, wherein the N- substituents oi said monoamide are hydrogen and an alkyl radical containing 8 to 22 carbon atoms, and the alkyl thlo'radical contains 1 to 17 carbon atoms.

4. A lubricant composition comprising a major amount of a hydrocarbon lubricating oil, and a minor amount sufficient to impart rust-inhibiting properties to the composition, oi a polyvalent metal salt oi a monoamide oi a 2.5-endoethylene- 2-methyl 5 isopropyl alkyl thio-cyclohexane- 1,6-dicarboxylic acid wherein the N- substituents are hydrogen and an alkyl radical containing 8 to 22 carbon atoms and the alkyl thio radical contains 1 to 17 carbon atoms.

5. A lubricant composition as defined in claim 4 in which the polyvalent metal salt is a barium salt.

6. A lubricant composition as defined in claim 4 in which the polyvalent metal salt is a magnesium salt.

7. A lubricant composition comprising a major amount oi a hydrocarbon lubricating oil and about 0.01 to 20 per cent by weight oi said 011, oi a polyvalent metal salt oi a monoamide oi a 2,8-endoethylene-2-methyl -5- isopropyl alkyl thio-cyclohexane-l,G-dicarboxylic acid wherein the N- substituents are hydrogen and an alkyl radical containing 8 to 22 carbon atoms, and the allryl thio radical contains 1 to 17 carbon atoms.

8. A lubricant composition as defined in claim 7 in which the N- substituents oi the monoamide. are hydrogen and a hexadecyl radical.

9. A lubricant composition as defined in claim "I in which the N- substituents oi the monoamide are hydrogen and an octadecyl radical.

10. A lubricant composition comprising a major amount of a hydrocarbon lubricating oil and about 0.01 to 20 per cent by weight oi said oil, oi the magnesium salt oi a monoamide oi 2,5- endoethylene-2- methyl 5 isopropyl-butyl thiocyclohexane-Lo-dicarboxylic acid wherein the N- substituents are hydrogen and a hexadecyl 11. A lubricant composition comprising a major amount or a hydrocarbon lubricating oil and-about 0.01 to 20 per cent by weight oi said oil, oi the barium salt oi a monoamide oi 2,5- endoethylene 2 methyl 6 isopropyl butyl thio-oyclohexane-1,6-dicarboxylic acid wherein the l t-substituents are hydrogen and a hexadecyl radical. V

,12. A polyvalent metal salt oi the condensation 'producgoi an alkanethiol containing 1 to 17 BEST AVAILABLE COPY boxylic acid and alkyl-substituted 2,5-endoethyiene A" cyciohexene-1,6 dicarboxylic acids which contain not more than four alkyl groups each having not more than 6 carbon atoms. wherein the N-substituents or said monoamide are selected from the group consisting oi hydrogen and alkyl and alkonyl radicals and containatotaloi8to22carbonatoms.

13. A polyvalent metal salt of a monoamide 01' a dicarboxyiicacid selected (mm the group consisting of 2,5-endoethyiene-alkyl thio-cyclohexane-1,6-dicarboxylic acid and alkyl-substituted 2,5-endoethylene-alkyl thio-cyclohexane-Lc-dicarboxylic acids which contain not more than tour alkyl m each having not more than 6 carbon atoms, wherein the N-sub- .stituents or said monoamide are hydrogen and e an .alkyl radicalcontaining 8 to 22 carbon atoms. sad the alkyl thio radical contains 1 to 17 carbon a ms.

14..- .A polyvalent metal salt as defined in claim 13 in which the N-substituents or said monoamidc are hydrogen and a hexadecyl radical.

15. A polyvalent metal salt as deflnedin claim 13 in which the N-substituents of said mono- 25 2 amide are hydrogen and an octadecyl radical.

1B. A polyvalent metal salt as defined in claim 13 in which the polyvalent metal is barium.

17. A polyvalent metal salt as defined in claim 18 in which the polyvalent metal is magnesium.

18. A polyvalent metal salt of a monoamide Of a 2,5-endoethylene-2-methyl-5-isopropy1-a1- kyl thio cyclohexane 1,6 dicarboxylic acid, wherein the N-substituents of said monoamide are hydrogen and an alkyl radical containing 8 to 22 carbon atoms, and said alkyl thio radical contains 1 to l'lcarbon atoms.

19. A polyvalent metal salt as defined in claim 18 in which said alkyl thio radical is a butyl thio radical and said polyvalent metal is barium.

20. A polyvalent metal salt as defined in claim 18 in which said alkyl thio radical is a butyl thio radical and said polyvalent metal is magnesium.

EDWARD MITCHELL.

WILLARD B. MORSE.

References Cited in the me of this patent UNITED STATES PATENTS Number Name Date Smith Sept. 24, 1946 2,458,425 Rocchini Jan. 4, 1949 

1. A LUBRICANT COMPOSITION COMPRISING A MAJOR AMOUNT OF A HYDROCARBON LUBRICATING OIL, AND A MINOR AMOUNT, SUFFICIENT TO IMPART RUST-INHIBITING PROPERTIES TO THE COMPOSITION, OF A POLYVALENT METAL SALT OF THE CONDENSATION PRODUCT OF (1) AN ALKANETHIOL HAVING 1 TO 17 CARBON ATOMS IN THE ALKYL GROUP AND (2) A MONOAMIDE OF A DICARBOXYLIC ACID WHEREIN THE TWO N-SUBSTITUENTS ARE SELECTED FROM THE GROUP CONSISTING OF HYDROGEN ALKYL AND ALKENYL RADICALS, AT LEAST ONE SUBSTITUENT BEING AN ORGANIC RADICAL OF SAID GROUP, AND WHEREIN THE TOTAL NUMBER OF CARBON ATOMS IN THE N-SUBSTITUENTS IS 8 TO 22, AND WHEREIN SAID DICARBOXYLIC ACID IS SELECTED FROM THE GROUP CONSISTING OF UNSUBSTITUTED AND ALKYL-SUBSTITUTED 2,5-ENDOETHYLENE - $3:4-CYCLOHEXENE-1,6-DICARBOXYYLIC ACIDS, SAID ALKYL-SUBSTITUTED DICARBOXYLIC ACID HAVING NOT MORE THAN FOUR ALKYL GROUPS EACH HAVING NOT MORE THAN 6 CARBON ATOMS. 